I don't exactly know what you are comparing. No popular IRC network came anywhere near what we would find acceptable in terms of reliability today. It was an absolutely (wonderful) wildfire.

Netsplits, where the entire IRC network would "split" into two (or more) effectively independent networks because some a link between two servers went down, were extremely common. I don't know if daily, or weekly, but common enough to be perceived as normal and expected in any case.

In the earlier days of IRC, netsplits were sometimes used for channel takeover. If someone was on a split off part of the net where there were so few people in the channel that they could obtain op status, they could kill and ban the "legitimate" ops when the nets joined back together.